Gil Weiss, 29, and Ben Horne, 32, fell off a ridge after reaching the west summit of 20,584-foot Palcaraju in the Cordillera Blanca range in mid-July, search coordinator Ted Alexander told The Associated Press.

Both belong to the pullharder.org climbers' collective, and Horne wrote about the first, six-day leg of their trip on its blog, saying they had been buffeted by hurricane-force winds when the two reached the top of the 20,216-foot Ranrapalca.

After a rest in Huaraz, the two set out again July 11 for an excursion of seven to 10 days. Their families contacted Alexander after 13 days passed with no word from them.

Weiss's sister, Galit, said the two were not carrying a satellite phone.

Horne was a graduate student in economics at the University of California, San Diego. Weiss was founder of a business a Boulder, Colo., business called Beyond Adventure Productions that specialized in organizing and photographing events in remote and spectacular locations.

The Cordillera Blanca climbing season runs from June to September, and the deaths of Weiss and Horne bring to eight the number of mountaineers who have lost their lives in the range so far this year, the AP said.